Non-recursive CNAME response format

[Barry Margolin]

In article <93cmqc$956 at pub3.rc.vix.com>,
Rob J Meijer <rmeijer at xs4all.nl> wrote:
>I am triing to implement a simple dns resequencer that receives
>A RR queries of names that don't fall into a known subdomain of a domain,
>and than checks if it can resequence the name tokens so that it does,
>and than send a CNAME response. I don't want my program to do recursion of
>the cname it finds, but I want the recursive nameserver that did the query
>to try and resolve the answer with the nameserver responsible for the
>found subdomain. The problem is that if I just send a rval=0 or rval=3
>with RA set to 0, and just a CNAME response, the calling nameserver does
>no further resolving by itself, and juturns my answer.
>What aditional records should be added to the response in order to
>convince the nameserver to resolve the A record less CNAME response?
>Or is it not valid for my program to send non-recursive CNAME responses to
>a A RR request?

The CNAME response *should* be sufficient.  Normally, the remote nameserver
will not even set the RD flag, so you wouldn't be expected to recurse even
if you had it available.

It sounds like there may be something else wrong in your response packet.
Maybe you could post a hex dump of it.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Burlington, MA
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